Kubbe — owner’s manual

Digital Reverberation System · Model KB-79. Manual as PDF.

1. Introduction

Kubbe is an algorithmic reverb with three rooms instead of a list of algorithms: Hammam, Cistern and Valley. Each room is a fixed character — its own reflection timing, decay and colour — inspired by a kind of space. Nothing in it is recorded or measured from a real place; there are no impulse responses. You pick a room, not an algorithm.

It ships as VST3, AU and Standalone on macOS (Apple Silicon and Intel), and as VST3 on Windows (64-bit).

The three rooms

• Hammam — inspired by a marble dome. Dense, bright first reflections, a flutter between parallel walls, a ring in the low mids.
• Cistern — inspired by an underground cistern. The column slaps arrive late and sparse, and the tail is long, dark, and moves slowly, like water.
• Valley — inspired by open air. The far slopes answer one by one, each answer darker and more blurred. With Echo Sync on, the echoes land on the beat grid.

2. Installation

Kubbe installs as an Audio Unit (AU) and a VST3 plug-in on macOS (Apple Silicon and Intel), and also runs there as a Standalone application. On Windows (64-bit) it installs as a VST3 plug-in.

macOS

1. Copy the .component (AU) into ~/Library/Audio/Plug-Ins/Components/, or the .vst3 into ~/Library/Audio/Plug-Ins/VST3/.
2. Restart your DAW, or make it rescan its plug-in list.

macOS — first launch

This build is not yet code-signed or notarised, so macOS Gatekeeper refuses to open it on a first double-click. To get past that once: in Finder, right-click (or Control-click) the plug-in or the Standalone app and choose Open, then confirm Open in the dialog that follows. macOS remembers the choice for that file.

Windows

1. If Windows blocks the downloaded files: right-click the zip, choose Properties, tick Unblock, then extract.
2. Copy the .vst3 folder to C:\Program Files\Common Files\VST3\.
3. Rescan plug-ins in your DAW.

3. Panel tour

The panel reads left to right, the way it was laid out on the rack unit: name and model plate, then PLACE, then the display cluster, then the control groups, then the switches.

1. Name block — KUBBE, “Digital Reverberation System”, and the MODEL KB-79 plate.
2. PLACE — three lit selector keys for the rooms: Hammam, Cistern, Valley. Switching room lets the old tail ring out for 1.5 seconds instead of cutting it.
3. Decay display (scope) — the energy per 20 ms and the Schroeder decay curve, measured live on an impulse run through the engine, with the T60 it reads printed on screen.
4. VFD readout — shows the value of the control you last touched for two seconds, then falls back to the measured T60 of the current room.
5. DUCK meter — a VU-style needle showing how far the tail is ducked right now, in dB.
6. LEVEL group — Mix.
7. TIME group — Decay, Pre-delay, Pre-delay Sync.
8. SPACE group — Distance, Width.
9. TONE group — Low Cut, High Cut.
10. DYNAMICS group — Duck.
11. FREEZE and ECHO SYNC switches. Echo Sync is only enabled when Valley is selected.

4. Controls

Control	Range · default	What it does
Place	Hammam / Cistern / Valley · Hammam	Selects which of the three rooms the engine runs. Everything else shapes that room; it does not blend between rooms.
Mix	0–100 % · 30 %	Dry/wet balance, equal-power law.
Decay	×0.25–×3.00 · ×1.00	Multiplies the room’s own decay time (RT60). The scope always shows the measured result, not a nominal number.
Pre-delay	0–250 ms · 0 ms	Added on top of the room’s own pre-delay (Hammam 7 ms, Cistern 42 ms, Valley 0 ms). Disabled when Sync is on.
Pre-delay Sync	Off, 1/64–1/4 · off	Replaces the Pre-delay knob with a value synced to the host tempo.
Distance	0–100 % · 50 %	Near (0 %): early reflections up front. Far (100 %): more room, darker, less of the direct reflections.
Width	0–150 % · 100 %	0 % collapses the wet signal to mono; 100 % is the room as built; up to 150 % widens it further.
Low Cut	20–1000 Hz · 20 Hz	High-pass on the wet signal only.
High Cut	1000–20000 Hz · 20000 Hz	Low-pass on the wet signal only.
Duck	0–100 % · 0 %	Follows the plugin’s own input — not an external sidechain. The tail steps back while that input plays, by up to 24 dB at full input level and full Duck. It ducks; it does not mute.
Freeze	On / off · off	Holds the tail indefinitely, level within about 3 dB, while input keeps playing. Shown as “FREEZE HOLD” on the VFD.
Echo Sync	On / off · off, Valley only	Valley’s five slope echoes land on the beat grid — 3/4, 5/4, 7/4, 5/2, 7/2 beats — instead of fixed millisecond spacing.

5. Recipes

Vocal air (Hammam)

Place: Hammam · Mix: 15–20 % · Decay: ×0.8 · Distance: 30 % · High Cut: 8 kHz · Duck: 40 %

Keeps the dome’s bright, dense early reflections up front without smearing diction; Duck lets the tail breathe between phrases.

Dark sustain (Cistern)

Place: Cistern · Mix: 25 % · Decay: ×1.2 · Pre-delay: 60 ms · Low Cut: 120 Hz · Width: 120 %

Lets the late column slaps arrive on their own before the long, dark tail fills in — good for pads and slow synth lines.

Rhythmic slope echoes (Valley)

Place: Valley · Echo Sync: on · Mix: 30 % · Decay: ×1.0 · Distance: 60 %

The five slope answers land on 3/4, 5/4, 7/4, 5/2 and 7/2 beats against the host tempo — a rhythmic, self-darkening echo rather than a straight delay.

Freeze pad

Any room · Mix: 100 % · Freeze: on · Width: 130 %

Holds whatever is in the tail as a sustained drone while you play or automate over it; unfreeze to let it fall away.

6. Specifications

Item	Value
Formats	macOS (Apple Silicon and Intel): VST3, AU, Standalone · Windows (64-bit): VST3
Channel layouts	Mono → Stereo, Stereo → Stereo
Code signing	macOS build not yet signed or notarised — see Installation

The three rooms (nominal, Decay at ×1.00)

Room	Built-in pre-delay	Nominal RT60 (mid)	Low cut	High cut
Hammam	7 ms	≈ 3.0 s	170 Hz	11.5 kHz
Cistern	42 ms	≈ 6.8 s	85 Hz	6.2 kHz
Valley	0 ms	≈ 1.9 s	240 Hz	8.2 kHz

These are each room’s built-in numbers at Decay ×1.00. The Decay knob scales them directly; the scope always shows the T60 actually measured for the current settings, not this nominal table.

Measured behaviour (self-test)

• Decay: each room’s T60 lands within range of its nominal value; Decay ×0.5 gives a shorter tail; output is finite and silent 24 s after an impulse.
• Echo Sync: Valley’s first echo lands on the 3/4 beat at 90, 120 and 140 BPM, within 3 ms.
• Freeze: the tail holds within 3 dB for 4 s while input keeps playing.
• Duck: at 100 % the wet signal drops 12–26 dB. It ducks; it does not mute.
• Determinism: identical output, bit for bit, across runs and across block sizes 512 and 97.
• Level: the three rooms sit within 4 dB of each other at full wet.
• Room switch: no output step larger than the signal already has.

Not done yet

• Code signing and notarisation on macOS.
• Switching room again while the previous tail is still fading cuts that older tail.

7. Licence

There is no demo or trial version. A licence comes from a purchase or from a free launch licence. Without one, the plugin shows an activation card and passes audio through untouched.

Activate

1. After checkout, Lemon Squeezy e-mails the licence key; a free launch licence is claimed on subverselab.com/launch. Signed in here with the same e-mail, the key is also under My plugins on your account page.
2. Open Kubbe in your DAW. The activation card covers the panel.
3. Paste the key and press Activate. This needs an internet connection once.

The activation is then stored on the computer and works offline. The plugin checks it again in the background about once a week; only a clear answer that the key is disabled, expired or released turns it off — a missing connection never does.

System	Where the activation is stored
macOS	~/Library/Application Support/SubverseLab/Licenses/
Windows	%APPDATA%\SubverseLab\Licenses\

Moving to another computer

A purchased key activates on one computer; a free launch licence on up to three. To move a key, open the plugin on the old computer and choose “Release this computer”, then paste the key on the new one.

1. On the old computer, open Kubbe and click the LICENSE label on the panel.
2. Choose Release this computer.
3. On the new computer, paste the same key into the activation card.

If the old computer is no longer available, write through the Help page from the e-mail address used at checkout.